The new development direction of PAN – based carbon fiber technology is reflected in three aspects: enhancing carbon fiber properties, matrix resin technology, and molding technology.
Enhancement of Carbon Fiber Properties
To meet application – specific performance requirements and balance strength, elastic modulus, and cost, several approaches are being explored. Compressive strength can be increased by 1.3 to 2.0 times through high – voltage – accelerated boron ion implementation, which refines the crystal structure. PAN – based carbon fiber has achieved an elastic modulus of 690GPa and a tensile strength of 3.4GPa. Interface control aims to boost impact resistance by balancing the bonding between carbon fibers and matrix resin via surface treatment of the carbon fiber interface. Efforts are also ongoing to reduce carbon fiber costs.
Matrix Resin Technology
This encompasses low – temperature – cured heat – resistant resins, hot – melt resins, and flame – retardant resins. Combining carbon nanofibers with carbon fiber resin prepregs enhances interlayer peel strength and compressive strength.
Molding Technology
The focus is on developing faster, cost – effective, and mass – production – suitable molding technologies and intermediate materials. High – speed molding technologies are being advanced, including resin infusion molding, resin film infusion molding (RFI), RTM molding, pultrusion molding, high – speed winding (FW) molding, and SMC/BMC molding. In aircraft part autoclave molding, automatic layering machines with digital control (NC) are being introduced to optimize curved prepreg layering efficiency. Fully automatic fiber placement technology is being developed for composite molding material layering. Non – heating molding technologies, such as electron beam and light curing, offer low – cost, high – performance manufacturing of large – scale structural composites. The evolution of RTM molding technology emphasizes mass production, low pressure, low temperature, and flexible reinforcement fiber settings. Integral molding of reinforcement materials, sandwich core materials, and inserts enables the production of large components like hulls. Additionally, the ACM thermoforming system is being developed for molding ACM sheets with continuous fiber – reinforced thermoplastic resin matrices.
